With the development of communications technologies, reducing power consumption of communications devices is becoming increasingly important. In the prior art, there is a power saving solution for a user equipment, where the solution provides a condition for triggering a server to send downlink data to a user equipment in a scenario in which the server sends data to the user equipment, thereby achieving an effect of saving power of the user equipment. A specific process is as follows:
The user equipment initiates a tracking area update (Tracking Area Update, “TAU” for short)/routing area update (Routing Area Update, “RAU” for short) request and starts to execute a TAU/RAU process; after receiving the TAU/RAU request, a core network control entity (for example, a mobility management entity (Mobility Management Entity, “MME” for short) or a serving general packet radio service support node (Serving General Packet Radio Service Support Node, “SGSN” for short)) indicates to the server (for example, a services capability server (Services Capability Server, “SCS” for short) or a machine type communication (Machine Type Communication, “MTC” for short) server) that the user equipment has sent the TAU/RAU request and instructs the server to send buffered downlink data to the user equipment; and the server sends the buffered downlink data to the user equipment according to the instruction of the core network control entity.
However, in this solution, each time receiving a TAU/RAU request sent by a user equipment (for example, an MTC device), a core network control entity needs to notify a server; and apparently, regardless of whether the server has downlink data to be sent to the user equipment, the user equipment needs to enable a receiver or a wireless module to wait for the downlink data of the server. Therefore, if the server has no data to be sent to the user equipment, time for the user equipment to wait is wasted. Especially for a user equipment that sends a TAU/RAU message frequently, waiting for multiple times is extremely adverse to power saving for the user equipment.